Steering lock for motor vehicles

ABSTRACT

A steering lock for motor vehicles comprises a locking element which prevents rotation of the vehicle&#39;s steering shaft (2) . The locking element is spring-loaded into a locking portion and can be shifted to the unlocking position against the action of the spring by a locking cylinder (3) and a rotary eccentric (16). The locking element consists of a locking sleeve (8) which surrounds the steering shaft (2), is mounted axially mobile but secured to remain fixed against rotation in the steering lock housing (1), and has locking teeth (12) at one end. The locking sleeve (8) co-operates with a locking ring (7) fastened to the steering shaft (2) and which also has locking teeth (11) at one end. An actuating lever (17) for the locking sleeve (8)is pivotally mounted in the steering lock housing (1), is provided with two arms (18, 19) which engage with the locking sleeve (8) or rest against the eccentric (16), and is loaded by a leg spring ( 23) which moves the locking sleeve (8) into the locking position, in which the locking teeth (12) of the locking sleeve (8) interlock with the locking teeth (11) of the locking ring (7).

The invention relates to a steering lock for motor vehicles with alocking element for preventing rotation of the vehicle steering shaft,the element being spring-urged into the locking position and beingcapable of being shifted into the unlocking position against the actionof the spring-loading by means of a lock cylinder acting through arotary eccentric.

Such motor vehicle steering locks are known in a range of differentforms, including those in which the locking element can only move intothe locking position under the action of its spring loading when the keyhas been partially or completely withdrawn from the lock cylinder or itscore. As a rule the locking element is in the form of an axially movablelocking bolt which engages in a notch in the steering shaft or in alocking sleeve secured to it. However other locking elements are alsoknown.

The invention is based on solving the problem of providing a steeringlock for motor vehicles of the kind stated in the introduction, which isof simple and light construction yet achieves effective and securelocking of the vehicle steering shaft and, in doing this, can withstandhigh torques.

This problem is solved by the features stated in the characterising partof claim 1. Advantageous embodiments of the motor vehicle steering lockaccording to the invention are given in the remaining claims.

In a motor vehicle steering lock according to the invention the lockingelement is formed by a locking sleeve which is displaceable along thesteering shaft and co-operates with a locking ring on the steering shaftso as to couple it mechanically to the steering each housing so that thesteering shaft can no longer be turned. A two-armed actuating lever isprovided for the locking sleeve and is pivotally mounted in the steeringlock housing and by means of which the locking sleeve is spring-urgedinto the locking position and is also movable into the unlockingposition by means of the eccentric actuated by the lock cylinder. Thespring loading is produced by a hairpin spring which engages on the onehand against the steering lock housing and on the other hand against theactuating lever.

If the lock cylinder is arranged in the steering lock housing in such away that its longitudinal axis and the longitudinal axis of the steeringshaft extend in mutually parallel planes and in fact at differentinclinations to a common reference plane perpendicular to these planes,then the pivotal axis of the actuating lever can extend in a thirdparallel plane and in fact perpendicular to the longitudinal axis of thelock cylinder, and the two arms of the actuating lever can be arrangedspaced apart and substantially perpendicular to one another so that theycan pivot in two mutually parallel planes which are perpendicular to thethird plane. As the longitudinal axis of the steering shaft makes, withthe pivotal plane of the arm which co-operates with the locking sleeve,the acute included angle by which the lock cylinder, of which thelongitudinal axis extends in the plane of pivoting of the arm thatcooperates with the eccentric, is inclined with respect to the steeringshaft, every pivotal movement of the arm that co-operates with thelocking sleeve causes a correspondingly reduced displacement of it alongthe axis of the steering shaft, which, for a given pivotal movement ofthe arm, is all the shorter, the greater is the acute angle.

In order to eliminate this reduction in view of the fact that alreadythe range is limited within which the actuating lever can be pivoted bymeans of the eccentric and the arm that co-operates with the lockingsleeve can move back and forth, it is of advantage to arrange thepivotal axis of the actuating lever both perpendicular to the axis ofthe lock cylinder and also perpendicular to the axis of the steeringshaft so that the arm of the actuating lever that co-operates with theeccentric is able to pivot in the plane containing the axis of the lockcylinder and parallel to the axis of the steering shaft and the arm ofthe actuating lever that co-operates with the locking sleeve islaterally movable substantially parallel to the axis of the steeringshaft. In this way any reduction of movement between the eccentric andthe locking sleeve is avoided, so that it can be shifted back and forthover a relatively long extent.

Two embodiments of the motor vehicle steering lock according to theinvention are described in the following by way of example inconjunction with the drawings.

In the drawings:

FIG. 1 is a side view of the first embodiment;

FIG. 2 is a plan view in the direction of the arrow II in FIG. 1;

FIG. 3 is a section along the line III--III in FIG. 1;

FIG. 4 is a section along the line IV--IV in FIG. 1;

FIG. 5 is a section along the line V--V in FIG. 3;

FIG. 6 is a section along the line VI--VI in FIG. 3;

FIG. 7 is a view looking in the direction of the arrow VII in FIG. 3;

FIG. 8 is a side view of the second embodiment;

FIG. 9 is a section along the line IX--IX in FIG. 8; and

FIG. 10 is a section along the line X--X in FIG. 8.

The two steering locks illustrated each comprise a housing 1 with twosleeve-shaped portions in which the hollow steering shaft 2 of theassociated motor vehicle and a lock cylinder 3 are respectivelyarranged. As can be seen in FIGS. 1 and 2 and in FIGS. 8 and 9 the twoportions of the steering lock housing 1 are arranged adjacent oneanother and mutually inclined so that the longitudinal axis 4 of thesteering shaft and the longitudinal axis 5 of the lock cylinder extendin mutually parallel planes L and SZ, and in fact at differentinclinations with respect to a common reference plane which isperpendicular to these planes L and SZ and accordingly to the plane ofthe drawing in FIGS. 1 and 8, in such a way that the two planescontaining respectively the axis 4 of the steering shaft and the axis 5of the lock cylinder and represented by the line III--III and IV--IV inFIG. 1 or by the line IX--IX and the lock cylinder axis 5 in FIG. 8 makea mutually included angle α of 30°. On that portion of it which enclosesthe steering shaft 2 the lock housing 1 is provided with externallongitudinal ribs 6 for adjustable securing to the vehicle.

Secured to the steering shaft 2 is a locking ring 7. Associated with itis a locking sleeve 8 which surrounds the steering shaft 2 and ismounted in the steering lock housing 1 or, rather, the relevant portionof it, to be secured against rotation, but to be able to move axially.For this purpose the locking sleeve 8 is provided with three externallongitudinal grooves 9 distributed uniformly around its periphery,engaged by three internal longitudinal ribs 10 of correspondingcross-section in the steering lock housing 1. The locking ring 7 and thelocking sleeve 8 each have a ring of locking teeth 11 or 12 on theirmutually opposed ends.

The lock cylinder 3 is provided with a rotatable and axially movablecore 13, to which is secured a switch spindle 14 extending co-axiallywith respect to the core 13 and serving on the one hand for actuating anignition and starting switch 15 secured on the steering lock housing oron the associated portion of it, and on the other hand for displacingthe locking sleeve 8. For this purpose the switch spindle 14 is providedwith an eccentric 16.

The displacement of the locking sleeve 8 takes place with the aid of anactuating lever 17 having two arms 18 and 19 and mounted to pivot in thesteering lock housing 1, in particular, in that portion of it which isassociated with the lock cylinder 3.

In the steering lock according to FIGS. 1 to 7 the pivotal axis 20 ofthe actuating lever 17 extends in a plane A parallel to the longitudinalplanes L and SZ of the steering shaft 2 and of the lock cylinder 3, andin fact perpendicular to the axis 5 of the lock cylinder. The two arms18 and 19 of the actuating lever 17 are arranged spaced apart along thepivotal axis 20 and in fact at the two ends of a sleeve-shaped centralportion 21 of the actuating lever 17, through which extends a bearingpin 22 and on which a hairpin spring 23 is mounted, with one of itslimbs engaging the actuating lever 17 or its arm 19 and the other limbengaging the steering lock housing 1. The two arms 18 and 19 areorientated substantially perpendicular to one another so as to extendacross from the switch spindle 14 towards the locking sleeve 8 and alongthe switch spindle 14 towards its eccentric 16.

The arm 18 of the actuating lever 17 that co-operates with the lockingsleeve 8 is provided with a ball-shaped end 24 by which it engages in aradial opening 25 in the locking sleeve 8, this opening being ofslot-like shape and extending in the direction of the periphery of thelocking sleeve 8. That arm 19 of the actuating lever 17 whichco-operates with the eccentric 16 on the switch spindle 14 is providedwith a safety pin 28 which is axially displaceable in a longitudinalbore 26 and is acted on by a helical coil compression spring 27 arrangedin the bore, the pin 28 co-operating with a radial projection 29 on theswitch spindle 14, as to be explained later, and which in the caseillustrated is a circular disc.

In the steering lock shown in FIGS. 8 to 10 the pivotal axis 20 of theactuating lever 17 extends between the lock cylinder 3 and the eccentric16 and perpendicular to the two mutually parallel planes L and SZ andtherefore also perpendicular to the axis 4 of the steering shaft and theaxis 5 of the lock cylinder, with the two arms 18 and 19 arranged spacedapart from one another and substantially perpendicular to one anotherfor acting on the locking sleeve 8 and for engaging the eccentric 16.The actuating lever 17 has a foot 30 perpendicular to the pivotal axis20 and having a sleeve-shaped end 31 through which extends the bearingpin 22 which is inserted in a wall 32 and an opposing cover 33 of thesteering lock housing 1, which embrace the sleeve-shaped end 31 of thefoot 30. The two arms 18 and 19 of the actuating lever 17 extendrespectively from the other end of the foot 30 away in the plane Fcontaining the pivotal axis 20 and the longitudinal axis 34 of the foot,towards the locking sleeve 8 or with an included acute angle β with theplane F along the switch spindle 14 to the eccentric 16, the arm 19which co-operates with the latter having an end 35 which is bent back atright angles towards the eccentric 16. Arranged on the sleeve-shaped end31 of the foot 30 of the actuating lever is the hairpin spring 23 whichwith its one limb engages a projection 36 on the foot 30 whilst itsother limb bears on the steering lock housing 1.

The arm 18 of the actuating lever 17 that co-operates with the lockingsleeve 8 engages with its free end in a matching radial opening 37 inthe locking sleeve 8. The safety pin 28 of the arm 19 co-operating withthe eccentric 16 on the switch spindle 14 and co-operating with theradial projection 29 on the switch spindle 14 is axially displaceable ina transverse bore 38 in the bent-back end 35 of the arm 19 and is loadedby a leaf spring 39. The leaf spring 39 is secured to the arm 19 andextends parallel to its bent-back end 35 and engages with its free endin a transverse groove 40 in the safety pin 28, provided at that end ofit which is furthest from the projection 29, and which projects from thebent-back end 35 of the arm 19.

The locking sleeve 8 is axially displaceable in the steering lockhousing 1, or rather in the relevant portion of it, between theunlocking position illustrated in FIGS. 3 and 9 and a locking positionin which its locking teeth 12 interengage with the locking teeth 11 onthe locking ring 7 so that the steering shaft 22 can no longer beturned. The hairpin spring 23, acting through the actuating lever 17,urges the locking sleeve 8 into the locking position from which thelocking sleeve 8 can be shifted into the unlocking position bycorresponding actuation of the lock cylinder 3 acting through theeccentric 16 and likewise the actuating lever 17, the actuating lever 17being pivoted by the eccentric 16 against the action of the hairpinspring 23.

In the steering lock according to FIGS. 8 to 10, on pivoting of theactuating lever 17, the arm 19 co-operating with the eccentric 16 on thebent-back end 35 moves in the plane SZ containing the axis 5 of the lockcylinder and parallel to the axis 4 of the steering shaft and the arm 18co-operating with the locking sleeve 8 moves substantially parallel tothe axis 4 of the steering shaft, and in fact the last-mentioned arm 18of the actuating lever 17 perpendicular to the axis of the arm, namelytransversely or laterally. The locking sleeve 8 is therefore movedthrough exactly the same distance by which the free end of the arm 18engaging in its radial opening 37 also shifts.

The steering lock is illustrated in the `Drive` position in which thelocking sleeve 8 is in the unlocking condition and the arm 19 of theactuating lever 17 or the bent-back end 35 of the arm 19 engages theeccentric on the switch spindle 14 and furthermore the ignition andstarter switch 15 completes the ignition circuit of the engine of thevehicle. In order to lock the steering shaft 2 against rotation, firstthe core 13 of the lock cylinder 3 is rotated by the use of the key 41placed in it, so that the eccentric 16 moves away from below the arm 19or, rather its bent-back end 35 and the ignition switch 15 interruptsthe ignition circuit to the engine of the vehicle. The actuating lever17 is then, it is true, no longer retained by the eccentric 16 in thatangular position which is shown in FIG. 4 or FIG. 8, but in fact by thesafety pin 28 of the arm 19 which engages against the projection 29 onthe switch spindle 14. Only when, after return rotation of the core 13into the initial position which permits insertion and removal of thekey, the key 41 is withdrawn from the core 13, can the actuating lever17 pivot back in a counter-clockwise direction from the position shownin FIG. 4 or 8 under the action of the hairpin spring 23, in order toshift the locking sleeve 8 into the locking position. In fact thewithdrawal of the key has the effect that the core 13 as well as theswitch spindle 14 displace axially to the right in FIG. 4 or 8, so thatthe projection 29 on the switch spindle 14 moves away clear of thesafety pin 28 of the actuating lever 17 and its support ceases.

Modifications of the embodiments which are illustrated and described areentirely possible. For example the side flanks 42 of the longitudinalgrooves 9 in the locking sleeve 8 and the side flanks 43 of thelongitudinal ribs 10 in the steering lock housing 1 could have anorientation different from that illustrated in FIGS. 6 and 10, which isradial with regard to the axis 4 of the steering shaft, in andparticular they could extend parallel to the respective centrallongitudinal plane 44 or could converge away from the base 45 of therespective groove and diverge away from the foot 46 of the respectiverib, which opposes spreading out of the steering lock housing 1 orrather of that portion of it which receives the locking sleeve 8, whenthe steering shaft 2, in its locked condition, is acted on by a largetorque. In particular in the steering lock shown in FIGS. 8 to 10 thelock cylinder 3 can be inclined in relation to the steering shaft 2 sothat the longitudinal axis 5 of the lock cylinder extending in the planeSZ makes an acute included angle α in the region of 20° to 60° with theprojection of the axis longitudinal 4 the steering shaft on the planeSZ.

I claim:
 1. A steering lock for the steering shaft of a motor vehiclehaving a locking element for locking the steering shaft againstrotation, said steering lock comprising:a steering lock housing, atleast a portion of said steering shaft being located in said steeringlock housing; a locking ring secured to the steering shaft within saidsteering lock housing and provided on one end with locking teeth; alocking sleeve surrounding the steering shaft, said locking sleevemounted non-rotatably but so as to be axially displaceable in saidsteering lock housing and said locking sleeve having locking teeth onone end thereof facing the locking teeth on said locking ring; actuatormeans mounted in the steering lock housing for engaging and axiallydisplacing said locking sleeve; a spindle rotatably supported withinsaid steering lock housing, said spindle having an eccentric mountedthereon for rotation with said spindle whereby upon rotation of saidspindle, said eccentric engages said actuator means to cause saidlocking sleeve to be axially displaced; means for biasing said lockingsleeve into a locking position wherein the locking teeth on said lockingsleeve engage the locking teeth on said locking ring to prevent rotationof said steering shaft; means for moving said locking sleeve into anunlocking position which comprises a lock cylinder having a rotatablecore connected to said spindle and being adapted to rotate in responseto manual rotation of a key receivable within said lock cylinder;wherein said actuator means comprises an actuator lever pivotallymounted about an axis intermediate its length within said steering lockhousing, said actuator lever including first and second arms, said firstarm being engageable with said locking sleeve for axially displacingsaid locking sleeve in response to pivoting of said actuator lever andsaid second arm being engageable by said eccentric for pivoting saidactuator lever; and wherein the axis about which said actuator leverpivots extends perpendicular to the longitudinal axis of the lockcylinder and in a plane parallel to two mutually parallel planesincluding the steering shaft longitudinal axis and the lock cylinderlongitudinal axis respectively, said lock cylinder being radially spacedfrom the steering shaft and inclined with respect to it, and the firstand second arms of said actuator lever being spaced from one another andsubstantially perpendicular to one another to extend across said spindletowards said locking sleeve and along the spindle towards said eccentricrespectively.
 2. A steering lock as claimed in claim 1, wherein saidlocking sleeve is spline connected to said steering lock housing tothereby prevent rotational movement of said locking sleeve butpermitting axial movement thereof, said spline connection beingconstituted by external longitudinal grooves formed on said lockingsleeve and internal longitudinal ribs of corresponding cross-section insaid steering lock housing, said longitudinal grooves and ribs includingside flanges which extend parallel to or converge in a directionextending away from the steering shaft.
 3. A steering lock as claimed inclaim 1, wherein said biasing means comprises a hairpin spring actingbetween said actuator means and said steering lock housing.
 4. Asteering lock as claimed in claim 1, wherein said spindle is alsoaxially movable within said steering lock housing when rotated to movesaid locking sleeve into said unlocking position, and furthercomprising:a projection fixedly secured to said spindle adjacent saideccentric; a bore located in an end portion of the second arm of saidactuator lever; and a spring-loaded safety pin located within said boreand being biased to engage said projection upon said axial displacementof said spindle and to prevent said actuator lever from displacing saidsleeve into said locking position until said key has been partially orcompletely removed from the lock cylinder.
 5. A steering lock for thesteering shaft of a motor vehicle having a locking element for lockingthe steering shaft against rotation, said steering lock comprising:asteering lock housing, at least a portion of said steering shaft beinglocated in said steering lock housing; a locking ring secured to thesteering shaft within said steering lock housing and provided on one endwith locking teeth; a locking sleeve surrounding the steering shaft,said locking sleeve mounted non-rotatably but so as to be axiallydisplaceable in said steering lock housing and said locking sleevehaving locking teeth on one end thereof facing the locking teeth on saidlocking ring; actuator means mounted in the steering lock housing forengaging and axially displacing said locking sleeve; a spindle rotatablysupported within said steering lock housing, said spindle having aneccentric mounted thereon for rotation with said spindle whereby uponrotation of said spindle, said eccentric engages said actuator means tocause said locking sleeve to be axially displaced; means for biasingsaid locking sleeve into a locking position wherein the locking teeth onsaid locking sleeve engage the locking teeth on said locking ring toprevent rotation of said steering shaft; means for moving said lockingsleeve into an unlocking position which comprises a lock cylinder havinga rotatable core connected to said spindle and being adapted to rotatein response to manual rotation of a key receivable within said lockcylinder; wherein said actuator means comprises an actuator leverpivotally mounted about an axis intermediate its length within saidsteering lock housing, said actuator lever including first and secondarms, said first arm being engageable with said locking sleeve foraxially displacing said locking sleeve in response to pivoting of saidactuator lever and said second arm being engageable by said eccentricfor pivoting said actuator lever; and wherein the axis about which saidactuator lever pivots extends perpendicular to two mutually parallelplanes including the steering shaft longitudinal axis and the lockcylinder longitudinal axis respectively, said lock cylinder beingradially spaced from the steering shaft and inclined with respect to it,and the first and second arms of said actuator level being spaced fromone another and substantially perpendicular to one another to be movablelaterally substantially parallel to the longitudinal axis of thesteering shaft and respectively to extend along the spindle towards saideccentric and to be pivotable in the plane including the lock cylinderlongitudinal axis.
 6. A steering lock as claimed in claim 5, wherein theaxis about which said actuator lever pivots is located between said lockcylinder and said eccentric and wherein said actuator lever includes afoot which is perpendicular to said pivot axis and from which said firstand second arms project, the first arm extending in a plane containingthe pivot axis of the actuator lever and the longitudinal axis of thefoot, and toward the locking sleeve, and the second arm including aportion extending at an acute angle with respect to said plane andtoward the eccentric and an end portion bent at a right angle thereto.7. A steering lock as claimed in claim 5, wherein said locking sleeve isspline connected to said steering lock housing to thereby preventrotational movement of said locking sleeve but permitting axial movementthereof, said spline connection being constituted by externallongitudinal grooves formed on said locking sleeve and internallongitudinal ribs of corresponding cross-section in said steering lockhousing, said longitudinal grooves and ribs including side flanges whichextend parallel to or converge in a direction extending away from thesteering shaft.
 8. A steering lock as claimed in claim 5, wherein saidbiasing means comprises a hairpin spring acting between said actuatormeans and said steering lock housing.
 9. A steering lock as claimed inclaim 5, wherein said spindle is also axially movable within saidsteering lock housing when rotated to move said locking sleeve into saidunlocking position, and further comprising:a projection fixedly securedto said spindle adjacent said eccentric; a bore located in an endportion of the second arm of said actuator lever; and a spring-loadedsafety pin located within said bore and being biased to engage saidprojection upon said axial displacement of said spindle and to preventsaid actuator lever from displacing said locking sleeve into saidlocking position until said key has been partially or completely removedfrom the lock cylinder.